If I'm working on a screenplay, I map out the emotions I want to convey in the script and create a playlist to listen to BEFORE I write, ideally in order of where the emotions would appear in the script. The list can include music from any genre and period.

Music while I'm writing tends to distract me from the task at hand. I used to create my own drones for the writing process using brain entrainment software in a constant loop and that worked fairly well.